Grodan Macro Plugs, Bag of 50, Case of 35 bags and 1750 plugs A great product for starting cuttings in your grow area. The Grodan Macro Plugs are round plugs with a slit that allows easy insertion of a cutting. These loose round plugs fit perfectly into the Gro-Block hole. For best results with these Macroplugs always insert them in a tray with individual cells. The individual cell will make sure the plug stays closed around the stem of your cutting. Macro Plug Round with Slit.